NAME

history - record of current and recently expired Usenet articles

DESCRIPTION

The file /var/lib/news/history keeps a record of all articles currently
stored in the news system, as well as those that have been received but
since expired. In a typical production environment, this file will be
many megabytes.
The file consists of text lines. Each line corresponds to one article.
The file is normally kept sorted in the order in which articles are
received, although this is not a requirement. Innd(8) appends a new
line each time it files an article, and expire(8) builds a new version
of the file by removing old articles and purging old entries.
Each line consists of two or three fields separated by a tab, shown
below as \t:
<Message-ID> \t date
<Message-ID> \t date \t files
The Message-ID field is the value of the article’s Message-ID header,
including the angle brackets.
The date field consists of three sub-fields separated by a tilde. All
sub-fields are the text representation of the number of seconds since
the epoch — i.e., a time_t; see gettimeofday(2). The first sub-field
is the article’s arrival date. If copies of the article are still
present then the second sub-field is either the value of the article’s
Expires header, or a hyphen if no expiration date was specified. If an
article has been expired then the second sub-field will be a hyphen.
The third sub-field is the value of the article’s Date header,
recording when the article was posted.
The files field is a set of entries separated by one or more spaces.
Each entry consists of the name of the newsgroup, a slash, and the
article number. This field is empty if the article has been expired.
For example, an article cross-posted to comp.sources.unix and
comp.sources.d that was posted on February 10, 1991 (and received three
minutes later), with an expiration date of May 5, 1991, could have a
history line (broken into two lines for display) like the following:
<312@litchi.foo.com> \t 666162000~673329600~666162180 \t
comp.sources.unix/1104 comp.sources.d/7056
In addition to the text file, there is a dbz(3z) database associated
with the file that uses the Message-ID field as a key to determine the
offset in the text file where the associated line begins. For
historical reasons, the key includes the trailing \0 byte (which is not
stored in the text file).

HISTORY

Written by Rich $alz <rsalz@uunet.uu.net> for InterNetNews. This is
revision 1.12, dated 1996/09/06.